A defiant Arsène Wenger has stood by his decision to substitute Alex Oxlade-Chamberlain for Andrey Arshavin, dismissing the need to justify a move that provoked a furious reaction from a section of the Arsenal support and even one of disbelief from his captain, Robin van Persie, during his side's 2-1 defeat on Sunday.

Wenger had opted to remove the lively Oxlade-Chamberlain, on his full Premier League debut, immediately after the teenager had set up the Dutchman for the hosts' equaliser against Manchester United, and with momentum building in Arsenal's favour. Van Persie had turned to the bench and, with arms stretched out, was seen to mouth "No", with Arshavin, who was booed on to the turf, subsequently culpable as United claimed a late winner.

The Arsenal manager was abused by some home supporters as a result of the decision, the mood turning more poisonous still once Antonio Valencia had exposed Arshavin to provide Danny Welbeck with the game's decisive goal. There was sarcastic applause offered by the fans near the dugout as the Frenchman threw down a water bottle in disgust. "I can understand that the fans are upset about the substitution, especially when it doesn't work," said Wenger. "But that means, first, I made the right decision at the start of the game.

"Oxlade-Chamberlain had started to fatigue, started to stretch his calf, and was not used to the intensity. He was sick during the week. Arshavin is captain of the Russia national team. I have to justify [substituting] a guy of 18 who's playing his second or third game? Let's be serious. I have to stand up for the substitutions I made. I've been 30 years in this job and have made 50,000 substitutions and I have to justify every time I make a decision? I do not have to explain to you every single decision I make."

While Wenger refused to comment on Van Persie's very public exclamation of disbelief at the change, suggesting he had not witnessed it, the former United defender Gary Neville, working as a pundit for Sky television, said: "If the captain's reacting like that, you've got problems."

Neville was more scathing still of Arshavin's subsequent contribution. "You don't like to criticise players, but he looks the most disinterested player in the league to me. He doesn't like our weather. He doesn't like our women. I think he wants to go back to Russia. Well, go back. The Arsenal fans don't want him out there."

"If you expect me to blame an individual player, it will not happen," said Wenger. "We win and lose together. You want me to blame one player? I will not do that. If I've made a mistake, I'm sorry. I'm like a player. I'm not completely sure. It could have happened as well if [Oxlade‑Chamberlain] had stayed on. That's part of United being dangerous on the flanks. But people pay for their tickets and are free to express their emotions. We cannot dictate what behaviour people should have. That doesn't mean they're right always."

While the Arsenal manager conceded defeat – a third in succession for the first time since 2007 – had left his team in "a very difficult position" in terms of Champions League qualification, Sir Alex Ferguson delighted in a win that ensured the gap to Manchester City at the top remains only three points. This game had felt all the more daunting after the leaders' stoppage-time victory over Tottenham Hotspur earlier in the afternoon, though Manchester's joint triumphs over north London have left the title pursuit as a two-horse race. "It is going to be hard for both us and City to collapse in the run-in now," said Ferguson. "We're both ahead of our other rivals and we just have to keep on City's coat-tails. We said that before the game that winning after City had won their game was the important thing. But we did it in the right way: we played football and were adventurous and had belief in ourselves. I'm delighted with that at this time of the season."

Ferguson anticipates being without Phil Jones for "a few weeks" after the player damaged ankle ligaments in the first half. The England defender will be scanned on Monday most likely along with Nani, who hopped from the field after sustaining his own ankle injury late on.